The annals of science are full of cat lovers. It turns out that plenty of famous scientists not only had cats, but they sometimes even credited their feline companions with helping them advance their work (or at least provide a welcome distraction from it). Here are five kitty collaborators who “worked” closely with some of history’s most well-known scientific names.
1. Albert Einstein and Tiger
Albert Einstein famously loved animals. “If a man aspired towards a righteous life, his first act of abstinence is from injury to animals,” he said, and was himself known to own multiple pets, including a dog and a parrot. But it was his cat Tiger who seemed to get the most attention, at least as far as posterity is concerned. Biographers have recorded that Einstein was sensitive to Tiger’s moods, noting for example that the cat got depressed when it was raining.
Cats apparently held a big enough place in Einstein’s heart that they pop up in quotes historically attributed to him. In his analogy explaining the telegraph, Einstein is said to have likened the technology to a long cat. “You pull his tail in New York and his head is meowing in Los Angeles,” he said.
Cats were less useful in helping to explain his own work in the special and general theories of relativity, which won him everlasting renown. Still, there can be little doubt that Einstein enjoyed Tiger’s company, especially when he had difficulties, as we all sometimes do, in his work and his life.
“There are two means of refuge from the misery of life: music and cats,” said Einstein.
2. Edwin Hubble and Nicholas
Even the least astronomy-minded reader knows the Hubble name, from the eponymous space telescope, if nothing else. Edwin Hubble was famous for his work in the first half of the 20th century. His discovery of galaxies beyond the Milky Way was revolutionary for the time, as was his work to support the theory that the universe is expanding. To say he helped redefine the field is a gross understatement. And he didn’t do it alone.
If there was a center to Hubble’s universe, you can bet that his cat, Nicholas Copernicus, lived there, making a beloved nuisance of himself. According to the Huntington Library, where Hubble’s personal papers are stored, references to the giant black cat abound in the archives.
He was clearly the darling of the family. Hubble frequently referred to his home as “Nicholas’ estate.” And in her diary, Hubble’s wife Grace noted the close bond between her husband and the cat. In a moment that every cat owner will recognize, Grace observed that when Edwin would retire to his study to work, Nicholas enjoyed lolling on Edwin’s desk, “sprawled over as many pages as he could cover,” she wrote. “‘He is helping me,’ [Edwin] explained.”
3. Isaac Newton and Spithead
Legend has it that, in between developing the fundamental laws of motion and gravitation, doing groundbreaking work on optics and helping to invent calculus, the great Sir Isaac Newton also found time to invent the cat flap.
Read more: 5 Eccentric Facts About Isaac Newton
As one version of the story goes, when Newton was at Cambridge, he requested that a hole be cut into his door and a leather or cloth flap put over it so that his cat, Spithead, could come and go at will. Cat owners the world over can easily envision the father of modern science being driven to distraction by the scratching and meowing of a cat wanting to be let out … then 30 seconds later yowling to be let back in. So, the story certainly feels true.
But feelings aren’t facts. While some scholars dispute whether Newton even had a cat, historical evidence makes it pretty clear that he didn’t invent the cat door. Apart from anything else, cutting a hole in a door — even one you might put a flap over — hardly qualifies as an invention.
Humans have been cutting holes in doors and walls for thousands of years — since before we even domesticated cats — to allow feral felines access to barns and granaries. They could then hunt the vermin that fed on our food supplies.
Read more: 5 Animals that Changed Humanity Forever
But as vermin attracts cats, so do great men often attract their share of legends over time, and Newton was no different. Fun as this cat tale is to relate, it’s as doubtful as that story about the apple clonking Newton on the head.
4. Erwin Schrödinger and Milton(?)
The most famous cat in science history owes its name to the physicist and Nobel laureate Erwin Schrödinger, who won the honor in 1933 for his early work in quantum mechanics. But he is best-known for the thought experiment involving a theoretical cat in a box, and whether it could be said to be both dead and alive. Schrödinger proposed the scenario in a 1935 paper as a criticism of quantum theory at the time.
People have sometimes wondered why Schrödinger used a cat in his example, instead of a rat or a plant or almost any other living thing. Some stories allege that Schrödinger had an actual cat, named Milton, and infer that the pet may have provided some inspiration to the physicist.
However, Milton may — and may not — have existed at all; evidence of Schrödinger's cat ownership is sketchy at best. But then Schrödinger, we’re compelled to note, was pretty sketchy himself.
5. Nikola Tesla and Macak
A brilliant but eccentric pioneer of electricity, Nikola Tesla has become something of an icon to science nerds everywhere. It turns out Tesla was a bit of a fanboy himself, at least when it came to his childhood pet, Macak, whom Tesla once described as “the finest of all cats in the world.”
In a letter written to a young admirer in 1939, Tesla extolled the cat’s virtues at some length; the man was in his 80s by then, but time had clearly not diminished Tesla’s love for Macak.
He told the story of a winter evening where he found himself stroking Macak’s back. In a moment that inspired his lifelong study of electricity, Tesla was shocked — literally — to discover that the cat’s back became “a sheet of light and my hand produced a shower of sparks loud enough to be heard all over the house.” It was a pretty dramatic moment — his mother told him to stop for fear he’d start a fire.
Luckily, for the Tesla family and for posterity, the only thing Macak sparked that night was the imagination and visionary mind of young Nikola, who waxed philosophical in the moment, wondering if the entirety of nature was but one giant cat, to be petted by the hand of God.
Yeah, your cat is saying, that sounds about right.
Read more: The 10 Greatest Scientists of All Time